drivers/net: return operator cleanup

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bmac.c b/drivers/net/bmac.c
index 9322699..a1b8c8b 100644
--- a/drivers/net/bmac.c
+++ b/drivers/net/bmac.c
@@ -1581,7 +1581,7 @@
 	int i;
 
 	if (bmac_devs == NULL)
-		return (-ENOSYS);
+		return -ENOSYS;
 
 	len += sprintf(buffer, "BMAC counters & registers\n");